The present invention relates to product packaging, and in particular to dispensing packages for fluid products, and the like.
Many different types of packages or containers are presently available for storing non-solid products of the type which are capable of flowing, such as fluid or fluidized materials, including liquids, pastes, powders, and the like, which substances are collectively and generically referred to herein as "fluids". Some such packages include a dispenser which permits a selected amount of fluid to be discharged from the package and then reseals to close the package.
Self-sealing dispensing valves have been used in packaging for certain types of products, such as the container disclosed in U.S. Pat. No. 4,728,006 to Drobish et al., which is designed for shampoos, conditioners, and the like. However, such valves can experience some sealing problems, as well as inconsistent dispensing flow rates, particularly when the packages are exposed to significant temperature variations. For instance, in most portions of North America, the ambient temperature varies greatly throughout the year, which results in some associated degree of temperature changes inside even air conditioned buildings, particularly between nighttime and daytime. For packages designed for use in special places, such as a household shower or bath, the temperature in the room can shift quite drastically during use. Dispensing packages used in such environments experience difficulty in maintaining consistent flow and sealing characteristics.
Furthermore, valves constructed from most conventional plastic materials cannot be used in certain types of packages since they either react with or adulterate the product. For instance, in food packaging, care must be taken to avoid valve materials which contain any type of toxins. Furthermore, active ingredients in products can cause the valve to either embrittle or soften, thereby ruining the designed flow rate and/or self-sealing characteristics of the valve.
Another drawback generally associated with prior art dispensing valve is their inability to consistently permit a preselected amount of air to be drawn or sucked back into the container after dispensing, while at the same time, maintaining a tight, secure seal that will prevent leakage even when the container is hung in an inverted orientation. When using containers of the type that have resiliently flexible sidewalls, the lack of sufficient air sucked back through the valve causes the container walls to at least partially collapse, thereby making further dispensing more difficult, and typically preventing, or at least greatly frustrating the user from getting all of the fluid out of the container.